Raman spectroscopy application in frozen carrot cooked in different ways and the relationship with carotenoids

Abstract

BACKGROUND: Raman spectroscopy, in its confocal micro-Raman variation, has been recently proposed as a spatially resolved method to identify carotenoids in various food matrices, being faster, non-destructive, and avoiding sample extraction, but no data are present in the literature concerning its application to the evaluation of carotenoid pattern changes after thermal treatment of carrots.

Application and optimisation of air–steam cooking on selected vegetables: impact on physical and antioxidant properties

“…The reduction of b *, in comparison to the raw sample, was more visible for the longer cooking times. The decrease of L * indicates darkening, while the reduction of both a* and b * indicates a general colour loss, as already reported for cooked carrots . These observations may be related to a decrease and/or isomerisation of α ‐ and β ‐carotene, the orange pigments of which the pumpkin is rich, as previously reported by other authors …”

“…reported a 9.5% increase of the total carotenoids extractability in pumpkin steamed for 5 min, in comparison to the raw ones. The higher a * and b * values of the steamed samples may be thus related to the extended extractability of this molecules, as already reported for carrots . The lower colour parameters of the air–steam cooked samples in comparison to the control, even at the same time and temperature conditions, suggest, also in this case, an extended oxidation due to the air.…”

“…The decrease of L* indicates darkening, while the reduction of both a* and b* indicates a general colour loss, as already reported for cooked carrots. 5,26 These observations may be related to a decrease and/or isomerisation of -and -carotene, 25 the orange pigments of which the pumpkin is rich, as previously reported by other authors. 27 wileyonlinelibrary.com/jsfa The control steamed sample showed higher a* and b* values than both the raw and air-steamed ones, except for the sample C5-110.…”

Effect of high hydrostatic pressure processing on textural properties and microstructural characterization of fresh‐cut pumpkin (Cucurbita pepo)

“…Nonenzymatic browning usually lead to darkening on vegetables and fruits, which is reflected in the significant decrease of L* values ( p < .05). The reduction of L*, a*, and b* after thermal process was already reported by previous researchers, which was result from oxidation and isomerization of β‐carotene (Camorani et al, ). HHP could maintain color characteristics much better than blanching, shown as a significant difference in L*, a*, and b* between heat and HHP group.…”

Effect of different cooking methods on structure and quality of industrially frozen carrots

“…Thus, steaming was the cooking method that more drastically affected the colour of frozen carrots. Recently, Camorani et al (2015) found that frozen carrots cooked under the same conditions used in this study exhibited carotenoids isomerisation with a significant increase in cis-β-carotene form. High correlations were found among all colour parameters and the ratio cis/all-trans-β-carotene, confirming the influence of the carotenoids isomerisation, as induced by heat treatment, on the final colour of the samples.…”